Finding the Fourth Proportional to 1,705.50, 2,558.85 and 840.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,705.50 : 2,558.85 = 840.42 : x
2. Step 2: Convert to fraction form
   1,705.50/2,558.85 = 840.42/x
3. Step 3: Cross multiply
   1,705.50x = 2,558.85 × 840.42
4. Step 4: Simplify right side
   1,705.50x = 2,150,508.72
5. Step 5: Solve for x
   x = 2,150,508.72/1,705.50
6. Step 6: Final answer
   x = 1,260.93